In-line type triple electron gun assembly

ABSTRACT

An in-line type triple electron gun assembly which comprises three electron gun members arranged in the same plane with the axis of the side gun members inclined at a predetermined angle to that of the central gun member; and support members fitted to the gun members for their integral assembly, said support member comprising two longitudinal elements each disposed between two adjacent gun members and at least one bridge element connecting said two longitudinal elements.

United States Patent 1191 Sawagata et a1.

[ 51 June 11, 1974 IN-LINE TYPE TRIPLE ELECTRON GUN ASSEMBLY [75] Inventors: Shinichi Sawagata, Tokyo;

Tokushirou Tanaka; Humiyuki Sato, both of Yokohama, all of Japan [73] Assignee: Tokyo Shibaura Electric Co., Ltd.,

Kawasaki-shi, Japan 22 Filed: o.11,1972

21 Appl. No.: 296,598

[30] Foreign Application Priority Data [58] Field of Search 313/268, 70 C, 70 R, 69 C, 313/251, 82 TS, 260, 261, 82 R, 69 R, 243,

3,258,625 6/1966 Johnson 313/257 3,603,829 9/1971 Tsuneta et a1. 313/70 C 3,659,133 4/1972 Tsuneta et a1. 313/70 C Primary ExaminerArchie R. Borchelt Assistant Examiner-Wm. H. Punter Attorney, Agent, or Firm-Flynn & Frishauf [5 7 ABSTRACT An in-line type triple electron gun assembly which comprises three electron gun members arranged in the same plane with the axis of the side gun members inclined at a predetermined angle to that of the central gun member; and support members fitted to the gun members for their integral assembly, said support member comprising two longitudinal elements each disposed between two adjacent gun members and at least one bridge element connecting said two longitudinal elements.

10 Claims, 6 Drawing Figures 56] References Cited UNITED STATES PATENTS 3,119,035 1/1964 Atti et a1 313/82 R i L F f i 2 14 T PATENTEDJIIIIH lam alaie'vae SHEET 2 BF 2 FIG.

lN-LINE TYPE TRIPLE ELECTRON GUN ASSEMBLY This invention relates to an in-line type triple electron gun assembly.

The prior art in-line type triple electron gun assembly is fabricated by fitting glass beads to the prescribed positions between two adjacent ones of three electron gun members arranged in the same plane by the aid of brackets fitted to grid electrodes constituting each electron gun member so as to fix together the three electron gun members.

With the prior art in-line type triple electron gun assembly, the glass beads are provided separately from each other, making the relative position of the gun members unstable and in consequence giving rise to their mutual displacement. Particularly, the brackets fitted to the grid electrodes constituting each gun member are bent intricately and subject to a certain degree of mechanical stress during fabrication, so that application of heat required for the assembly of gun members most likely deforms the brackets. Though very slight for the individual brackets, this deformation assumes a prominent proportion for all the brackets, resulting in the noticeable displacement of the electron gun assembly as a whole. This displacement of the constituent gun members occurs particularly in their axial direction, leads to the irregular arrangement of its grid electrodes.

It is accordingly the object of this invention to provide an electron gun assembly whose constituent members are accurately arranged to keep the assembly as a whole free from any deformation.

SUMMARY OF THE INVENTION According to this invention, triple electron gun members each having a cathode electrode, plane grid electrode and cylindrical electrodes coaxially arranged in succession are placed side by side in the same plane with a prescribed convergence angle defined therebetween. To both sides of the electron gun assembly are fused two support members to hold the respective gun members securely in place. Each support member comprises at least one lateral or bridging component fused in common to at least the cathode electrodes and plane grid electrodes of the respective electron gun members and at least one longitudinal component intersecting said at least one lateral component at right angles and fitted in common to said electron gun members through the later described means which are fused to said electron gun members.

The present invention can be more fully understood from the following detailed description when taken in connection with the accompanying drawings, in which:

FIG. 1 is a side view of an in-line type triple electron gun assembly according to the first embodiment of this invention;

FIG. 2 is a sectional view on line 2-2 of the electron gun assembly of FIG. 1;

FIG. 3 is a perspective view of a plane grid electrode of a side electron gun member;

FIG. 4 is a perspective view of a plane grid electrode of a central electron gun member;

FIG. 5 is a side view of a triple electron gun assembly according to the second embodiment of the invention; and

FIG. 6 is a sectional view on line 66 of the triple electron gun assembly of FIG. 5.

As seen from FIG. I, each electron gun member 12 of an in-line type triple electron gun assembly 11 comprises a cathode electrode 13, a first plane grid electrode 14 and second to fourth cylindrical grid electrodes 15 to 17, all coaxially arranged in succession. Said electron gun assembly 11 comprises triple electron gun members 12 each having the abovementioned arrangement, and a magnetic convergence assembly 18 disposed ahead of the furthest end of the fourth cylindrical grid electrodes of the electron gun members 12. The juxtaposed triple electron gun members 12 are securely held between two generally H- shaped support members 19 made of, for example, glass. The cathode electrode 13 of the electron gun member 12 comprises a heater received in a generally funnel-shaped support member 20. The first plane grid electrode 14s of each side electron gun member 12 comprises, as shown in FIGS. 2 and 3, a semicircular effective plate electrode 22 bored with a hole 21s for allowing the passage of a beam of electrons and an electrode holder 23 erected on said plate electrode 22, thus presenting an L-shaped cross section as a whole. Both side grid electrodes 14 each constructed as described above are so disposed as to cause the electrode holders 23 to face each other. As shown in FIG. 4 first plane grid electrode Me of the central electron gun member 12 comprises a channel-shaped effective grid electrode 24 bored with a hole 21c allowing the passage of a beam of electrons and electrode holders 25 projecting outward from both ends of said effective electrode 24.

The H-shaped support member 19 is so designed that when it is fused to the electron gun assembly 11, the lateral component 1% bridging the two longitudinal components 19a is so positioned as to face the first grid electrode and cathode electrode of each electron gun member 12. As shown in FIG. 1. lateral component 19b is integral with (i.e., integrally connected to) components 19a and is made of the same material as components 19a. Said I-I-shaped support member 19 is fitted to the electron gun assembly 11 through the support member 20 of the cathode electrodes 13, the holders 23 and 25 of the first plane grid electrodes 14s and 140, and brackets 26 fused to the cylindrical grid electrodes 15 to 17. A metal support element 19C bridges the ends of the H-shaped support member 19.

According to the in-line type triple electron gun assembly of this invention of the aforementioned arrangement, the three electron gun members 12 are fixed in place by the I-I-shaped support members 19, so that the respective electron gun members 12 and the electrodes included therein can be located accurately with the support members 19 used as the base. Since the electron gun members 12 are substantially free from any deformation or distortion, a beam of electrons emitted from the electron gun members 12 can display excellent characteristics of emission and focusing simply by slightly adjusting an external magnetic field. Further, the electrodes of the electron gun members 12 are independently supported by the H-shaped support members 19, so that the brackets 26 are required to hold only the grid electrodes to which they are fused, namely, are not subject to any extra load. Therefore, the brackets 26 can be made of thin light material having a relatively small mechanical strength.

This offers various advantages that the brackets 26 can be easily fabricated; work stress occurring in the brackets 26 is reduced; when the thin brackets 26 are fused to the electrodes the roundness of said electrodes is little affected; and the electron lens constituted by the electron gun members is substantially free from aberration.

The lateral component 19b of the H-shaped support member 19 is fused to the first plane grid electrode and cathode electrode of each electron gun member, thereby minimizing the deformation of the mechanically weak first plane gride electrode which would occur when the triple electron gun members are assembled and the harmful effect of displacement caused by said distortion between the axis of the first grid electrode and those of the other grid electrodes. Further, the above-mentioned lateral component 19b plays the part of elevating the overall mechanical strength of the electron gun members constituting the in-line type electron gun assembly which is mechanically weaker than the delta-shaped type.

There will now be described by reference to FIG. 5 the second embodiment of this invention. The triple electron gun members arranged in the same manner as in the first embodiment have the electrodes operated with the same potential or three juxtaposed electrodes. The three electron gun members 12 are securely held between two insulating support members 30 each formed of lateral components 31, 32, 33 and 34 fused to the respective crosswise groups 13, 14, 15, 16 and 17, each group consisting of said three juxtaposed electrodes and a longitudinal component 35 intersecting said lateral components at right angles. Lateral components 31-34 are integral with and are made of the same material as the longitudinal component 35.

The electron gun assembly of the second embodiment shown in FIG. 5 attains not only the same effect as the first embodiment but also displays the following advantage that since the lateral components support the crosswise groups each consisting of three juxtaposed grid electrodes operated with the same potential, the electrodes of the lengthwise groups operated with different potentials can be spaced relatively far from each other, thereby elevating the degree of insulation therebetween.

What we claim is:

1. An in-line type triple electron gun assembly comprising:

three electron gun members, each of which comprise a cathode electrode, plane grid electrodes and cylindrical grid electrodes, all coaxially arranged in succession, said three electron guns being located side by side in the same plane with a prescribed convergence angle defined therebetween;

two support members for supporting said three electron gun members therebetween, each supporting member being fitted to said gun members and including at least one longitudinal component and at least one lateral component which are made of the same material and formed integrally in a predetermined shape, said longitudinal component extending in the lengthwise direction of said electron gun assembly and said at least one lateral component extending laterally from said longitudinal component; and

a convergence assembly positioned ahead of the forward end of said three electron gun members.

2. An electron gun assembly according to claim 1 wherein said at least one lateral component of at least one of the support members is fused to the cathode electrodes and plane grid electrodes of electron gun members.

3. An electron gun assembly according to claim 1 wherein said at least one lateral component of at least one of the support members is fused to the cathode electrodes and plane grid electrodes of all of the electron gun members.

4. An electron gun assembly according to claim 1 wherein each of said support members is generally H- shaped and comprises two longitudinal components and a lateral component bridging said two longitudinal components.

5. An electron gun assembly according to claim 4 wherein said lateral component of at least one of the H-shaped support members is fused to the cathode electrode and plane grid electrodes of electron gun members.

6. An electron gun assembly according to claim 4 wherein said lateral component of at least one of the H-shaped support members is fused to the cathode electrode and plane grid electrodes of all of the electron gun members.

7. An electron gun assembly according to claim 4 wherein said generally H-shaped support members each include a metal support member bridging the ends of the longitudinal components thereof.

8. An electron gun assembly according to claim 5 wherein said generally H-shaped support members each include a metal support member bridging the ends of the longitudinal components thereof.

9. An electron gun assembly according to claim 1 wherein each of said support members comprises one longitudinal component and a plurality of lateral components integrally connected to said longitudinal component.

10. An electron gun assembly according to claim 9 wherein at least one of said lateral components is fused to the cathode electrodes and plane grid electrodes of electron gun members. 

1. An in-line type triple electron gun assembly comprising: three electron gun members, each of which comprise a cathode electrode, plane grid electrodes and cylindrical grid electrodes, all coaxially arranged in succession, said three electron guns being located side by side in the same plane with a prescribed convergence angle defined therebetween; two support members for supporting said three electron gun members therebetween, each supporting member being fitted to said gun members and including at least one longitudinal component and at least one lateral component which are made of the same material and formed integrally in a predetermined shape, said longitudinal component extending in the lengthwise direction of said electron gun assembly and said at least one lateral component extending laterally from said longitudinal component; and a convergence assembly positioned ahead of the forward end of said three electron gun members.
 2. An electron gun assembly according to claim 1 wherein said at least one lateral component of at least one of the support members is fused to the cathode electrodes and plane grid electrodes of electron gun members.
 3. An electron gun assembly according to claim 1 wherein said at least one lateral component of at least one of the support members is fused to the cathode electrodes and plane grid electrodes of all of the electron gun members.
 4. An electron gun assembly according to claim 1 wherein each of said support members is generally H-shaped and comprises two longitudinal components and a lateral component bridging said two longitudinal components.
 5. An electron gun assembly according to claim 4 wherein said lateral component of at least one of the H-shaped support members is fused to the cathode electrode and plane grid electrodes of electron gun members.
 6. An electron gun assembly according to claim 4 wherein said lateral component of at least one of tHe H-shaped support members is fused to the cathode electrode and plane grid electrodes of all of the electron gun members.
 7. An electron gun assembly according to claim 4 wherein said generally H-shaped support members each include a metal support member bridging the ends of the longitudinal components thereof.
 8. An electron gun assembly according to claim 5 wherein said generally H-shaped support members each include a metal support member bridging the ends of the longitudinal components thereof.
 9. An electron gun assembly according to claim 1 wherein each of said support members comprises one longitudinal component and a plurality of lateral components integrally connected to said longitudinal component.
 10. An electron gun assembly according to claim 9 wherein at least one of said lateral components is fused to the cathode electrodes and plane grid electrodes of electron gun members. 